local lock_key = 'L_'..tostring(KEYS[1]);
local queue = 'Q_'..tostring(KEYS[1]);
local lock = redis.call('setnx',lock_key,1);
if(lock == 0)
then
    return -1;
end
local pwd = redis.call('hget',KEYS[1],KEYS[2]);
redis.call('del',lock_key);
return pwd;